What You Should Know About Diamond Certifications

All Jared loose diamonds, as well as some diamonds already set into jewelry, have been graded by an independent lab before making their appearance in store. The report from that evaluation is called a diamond certificate - also known as a diamond grading report, diamond dossier, diamond quality document or diamond light performance certificate. This document gives you important information that can help you to make an informed diamond purchase.

The 4C's of diamond quality

The color, clarity, cut and carat weight of a specific diamond as viewed under magnification.

A diamond's characteristics

Proportions, finish, and treatments.

Depending upon the diamond, you may also receive a light performance certificate

Light performance measures the bright white light (brilliance), bright color light (fire) and scintillation (sparkle) of a diamond.

The Gemological Institute of America (GIA)

GIA pioneered diamond grading in the 1940s, creating a consistent way to describe a diamond in common language. Today, GIA grading certificates are considered the hallmark of integrity in the diamond world. The private laboratory issues two types of reports:

The GIA Diamond Grading Report provides scientifically determined information on shape, clarity, color, cut, carat weight, proportions, finish and treatments. It also includes a diagram of the diamond showing any inclusions that affect clarity.
The GIA Diamond Dossier® is a more concise version of the full report and is available for loose diamonds between .15 and 1.99 carats.

Gemological Science International (GSI)

GSI is an independent gemological laboratory based in the heart of New York City's Diamond District with additional offices in diamond centers around the world. GSI offers gemstone identification, grading and appraisal services exclusively to the fine jewelry industry. The lab's business model is built on integrity, innovation, professional service and shared research education.

GemEx Systems

GemEx is an independent laboratory that focuses on light performance, or the movement of light through the diamond. Trained professionals use the GemEx BrillianceScope® Analyzer to measure a diamond's white light (brilliance), color light (fire) and scintillation (sparkle). These measurements are then compared to those of other diamonds of the same shape. The highest and lowest amount of white light, color light and scintillation possible for each shape was set by measuring thousands of diamonds. The GemEx Light Performance Report illustrates the measurements for your diamond in a three-bar graph.

GEMEX SYSTEMS

How Is Light Performance Determined?

GemEx ratings are determined by the use of BrillianceScope® Analyzers, which measure a diamond's:

Brilliance, or white light.
Fire, or color light.
Sparkle, or scintillation.

How Do I Read My GemEx Certificate?

The GemEx certificate identifies your diamond and grades it against other diamonds with a similar shape. Each certificate includes:

A bar graph that serves as a quick reference for a diamond's Brilliance, Fire and Sparkle.
Five light measurements based on light performance at different angles.
An image of your diamond.

American Gem Society (AGS)

AGS Laboratories developed the AGS Performance-Based Cut Grading System. The key to the system is tracing light as it travels through the diamond. That's what determines whether a diamond looks bright and lively or dull and mediocre. The lab offers several levels of grading reports. The most popular is the Diamond Quality® Document. It shows cut (if available), color, clarity and carat weight accompanied by a profile showing that individual diamond's measurements, along with a custom plot for the actual facet arrangement and inscription details.

International Gemological Institute (IGI)

IGI is an independent grading and appraisal organization with centers in New York City and Los Angeles, as well as in Antwerp, Bangkok, Mumbai, Tokyo, Dubai and Toronto. Several gemologists carefully analyze each diamond and produce an accurate description of its characteristics, such as color, clarity, carat weight and the quality of its cut. The information is stored in IGI's computer database so you may request an update of your report if the need arises. IGI also offers colored gemstone certificates, educational courses and laser inscription services.